What is the smallest positive integer n such that, out of the n unit fractions 1/k where 1≤k≤n, exactly half of the fractions give a terminating decimal?
Isn't it 6 integers as follows:
2, 3, 4, 5, 6, 7.
1/2, 1/3, 1/4, 1/5, 1/6 and 1/7 - which gives 3 terminating and 3 non-terminating
So, the smallest positive integer n = 7
you have to start with k=1.
The answer is 12
+586 
